Absorptive glass

ABSTRACT

Glass having an extremely high absorption coefficient for incident light in fiber optical image transfer devices and working compatibility with conventional light-conducting glasses used in the manufacture of such devices.

i l-361130 SR iJnited Stat 14 1 Aug. 26, 1975 1 1 ABSORPTIVE GLASS [75] Inventor: Jimmy C. C. Wu, Southbridge,

Mass.

[73] Assignee: American Optical Corporation,

Southbridge, Mass.

Primary ExaminerLe1and A. Sebastian [22] Filed: Jan. 3, 1969 Attorney, Agent, or Firm-William C. Nealon 21 App]. No.: 790,512

[57] ABSTRACT [52] U- C 0 7 350/96 B Glass having an extremely high absorption coefficient [51] Int. Cl. .Q C03C 3/30 f in id t light in fiber optical image transfer de- 1 Field o 33 1 1 p vices and working compatibility with conventional light-conducting glasses used in the manufacture of [56] References Cited such devices.

UNITED STATES PATENTS 2,996,390 8/1961 Wcissenbcrg et a1. 106/47 0 8 Clams No Drawmgs OR IN 106/4712 1 r ABSORPTIVE GLASS BACKGROUND OF THE INVENTION 1. Field of the Invention Glass compositions relating more particularly to improved light absorptive glass materials for use in fiber optical image-transfer devices.

2. Description of Prior Art Fiber optical image-transfer devices such as are shown in application Ser. No. 238,372, now U.S. Pat. No. 3,387,959, entitled Fiber Optical Image Transfer Devices and MEthod of Making the Same, filed Nov. 19, 1962 and assigned to the same assignee as the present invention, have light-conducting optical fibers secured in bundled side-by-side relation with each other. Each optical fiber comprises a core filament, frequently formed of a lanthanum borate glass material surrounded by a cladding of a different glass material. The core filament material is of relatively higher refractive index than the fiber cladding material. lnterspersed within this bundle between the light-conducting optical fibers are lightabsorbing fibers each having a core filament of absorptive glass material surrounded by a cladding of a different light-transmitting glass material. Usually the same material is used for cladding both the light-conducting and light-absorbing fibers so that the claddings of both types of fibers can be easily fused together to form a vacuum-tight bundle of fibers. It will be understood that the core filaments and fiber cladding materials must be of compatible fusing temperature, drawing temperature, viscosity, coefficient of thermal expansion and the like so that the filament cores can be clad by conventional techniques and so that the fibers can be readily fused together. Particularly where the light-conducting fibers are to be drawn together with light-absorbing fibers to form multifiber units, it is desirable that the cores of both types of fibers be of compatible fusing temperature, drawing temperature etc. It will also be understood that, in order to perform their function as described in said copending application, the light-absorbing core materials are preferably adapted for extremely high absorption of incident light.

SUMMARY OF THE INVENTION The absorptive glass material provided by this invention incorporates mixtures of phosphate pentoxide (P and either molybdenum trioxide (M00 or vanadium pentoxide (V 0 or both as its principal glass forming ingredients. Phosphate pentoxide is preferably used within the range from approximately 14 to 35 weight percent of the glass composition, molybdenum trioxide is preferably used within the range of approximately 0 to 45 weight percent of the composition and the vanadium pentoxide is preferably used within the range from approximately 0 to 35 weight percent of the composition. When both of the latter two ingredients are used at the same time, the range for the M00 will be between approximately 25 to 45 weight percent of the composition and the range for the V 0 will be between approximately and 29 weight percent of the composition. Such glass materials may also incorporate calcium oxide (CaO) within the range of approximately 0 to 5 weight percent. The glass compositions of this invention may further embody ferrous oxide (Fe O this ingredient preferably being incorporated within the range from approximately 5 to 15 weight percent. In addition, these glass materials can also incorporate other ingredients such as tungsten trioxide (W0 within the range from about 0 to 30 weight percent, barium oxide (BaO) within the range from approximately 0 to 15 weight percent. Additionally other ingredients which may be included are cobalt oxide (C0 0 in the weight percent range of approximately 0 to 8%, manganese dioxide (MnO in the weight percent range of approximately 0 to 10%, nickel oxide (NiO) in the weight percent range of approximately 0 to 5%, cupric oxide (CuO) in the weight percent range of approximately 0 to 5%, and chromium oxide (Cr O in the weight percent range of approximately 0 to 3%.

In accordance with this invention, the highly absorptive glass materials incorporate the manganese dioxide (MnO within the above range for improving the optical density properties of the glass. In addition, these glass materials may incorporate one or more of the above-mentioned ingredients C0 0 NiO, CuO and Cr O as additional colorants for further increasing the optical density of the glass materials.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The various ingredients of the glass materials of this invention can be varied within the limits as described so that the calculated composition of the glass materials can be set forth as follows:

Percent by Weight P 0 14 to 44 V 0 O to 35 M00 25 to 45 W0 0 to 30 CaO 0 to 7 BaO 0 to 15 R2 0 5 to 15 C0 0,, 0 to 8 MnO 0 to 10 NiO 0 to 5 CuO 0 to 5 Cr O 0 to 3 said glasses having an optical density, that is of total integrated transmission for the optical region of less than 0.5% in a sample sheet of glass of approximately microns thickness.

It is pointed out that a particular feature of this invention is that the principal glass forming ingredients, for example, P 0 V 0 and M00 are, in combination, both colorants and network formers which produce the glass. However, additional colorants may be added as already indicated above.

Specific examples of compositions which have given good glasses having at least the light absorption properties desired are as follows:

-Continued -Continued Composition B F030.1 45.40

Percent by Weight Example D 150 14.86 5 V205 28.45 Parts by Weight M003 3740 N114 PQ 214.80 CaO 1.16 V502 102.40 BaO l0.00 W03 7750 F630 821010;, )2 123.25 1O Fe O 36.50 Composition C 2 8; Percent by Weight P 0 26.00 c1 0 3.50 Moo 28.32 wo 27.42 Ca; 0 8 Example E BaO 8.37 F6304 908 Parts by Weight NH. 11,1 0 113.40 Composition D V502 127-25 M003 152.00 Percent by Weight 0 10-00 26 52 CaCO 19.30 P105 13-5040, 102.00 V205 20.48 F860 30 65 W03 15.50 C 6 10'Q0 BaO 14.50 2 19-30 Fe O 7.30 Nio 00 0 3.20 O Mno 8.50 Cuo NiO 1.30 CuO 2.00

cr o 0.70

According to this invention, the described raw batch Composition E ingredients are weighed out and are finely ground and mix in conventional manner and are referabl Percent by Weight ed p y P o 1400 placed and melted in a platinum cruclble. During the V 0 25.45 melting of the glass batch it is preferably stirred with a x23 3-38 conventional platinum stirrer for homogenization and d fining operations under controlled heating conditions. 2 The homogenized and fined glass is then cast into 2 molds of metal, graphite or ceramic refractory materi- M 2 als of any shape desired. 3:? 5:28 The absorptive glasses of this invention are durable and stable and are chemically and thermally compatible with conventional glasses employed in optical fi- Preferred raw batch compositions for achieving the bets. The glasses are of good quality and are substanspecific glass just mentioned are as follows: tially free of bubbles, seeds and other inclusions. Generally, the glasses do not tend to bloom (form surface films) or to devitrify as do other extremely absorptive Raw Batch Compositions In Grams glasses. In particular, the improved absorptive glasses Example A have fusing temperatures, drawing temperatures, viscosities and coefficients of thermal expansion compati- Parts by Weight NH H Po 120 35 ble with the lanthanum borate glasses conventionally V"2 2 4 212 50 employed as core materials in light-conducting optical 3 18790 fibers. The absorptive glasses can be readily drawn, Caco 1 d d fu d t th 'th t 1 t' lfb Bamoah 6800 c a an se oge er w1 conven 1ona op 10a 1 er F 3 4 38-88 glass materials and, when embodied in fiber optical C030 image transfer devices such as already noted can be Example B conveniently ground and polished by conventional Pans by weight techniques. 'Ijhese novel glass materials are also chemi- NH H PO 120 35 cally compatible with phosphors and the like convenv 6, 2 4 142.25 tionally employed with fiber optical image-transfer de- 8700 vices. 02100 10-35 I Ramos)2 0200 t w1ll be understood that the examples of glass mate- F6304 3065 rials described herein have been described by way of Example C illustration and that this invention includes all modifications and equivalents of said glasses which fall within Pans by weght the scope of the appended claims. H PO 210.60 2 I claim Moo 141-60 w 137.10 1. An absorptive glass material of a composition concaco, 7.25 I Eamon): 7H5 sistmg essentially of the followlng Ingredients.

i in a thickness of 80 microns.

5. An absorptive glass material according to claim 1 and having the following ingredients: Percent by Weight P20... 14 to 44 i V 0 to 35 5 Percent by Weight M00 0 to 45 W0 0 to 30 P 0 26.52

C210 0 to 7 V 0 20.48

BaO 0 to l5 W0 15.50 Fe -,O 5 to l5 BaO l4.50 C0 0 0 to 8 Fe ,0., 7.30 MnO 0 to l0 l0 C0 0 3.20

MO 0 to 5 Mno 8.50

CuO 0 to 5 MO 1.30 Cr O 0 to 3 CuO 2.00

CEO-i 0.70.

said glass having a total integrated light transmission i for the optical region of the spectrum of less than 1.0% 0 absorpuve glass material accordmg to clam! 1 and having the following ingredients:

2. An absorptive glass material according to claim 1 having the following ingredients: Percent y weight Percent by Weight V 0 25.45

P 0 l4.86 W0 2.00 V 0 28.45 CaO 2.16 M00 37.40 BaO l 2.00 CaO 1.16 5 F9 0,, 6.13 13230 8.00 Co Q, 2.00 Fe O 6. l3 MnO 3.86 C0 0 .00. NiO 0.50

CuO l .50.

3. An absorptive glass material according to claim 1 and having the f ll i ingredients; 7. An absorptive glass material according to claim 1 and having the following ingredients:

Percent by Weight Percent by Weight P205 i486 20, 28-45 v 0. l8.8 M003 37.40 540C)3 3L4 Q10 H6 P 0. 43.6 o 10.00 d 6.2. F6304 6. l 3 (30.0. 2.00.

4. An absorptive glass material according to claim 1 and having the following ingredients:

and having the following ingredients:

Percent by Weight Percent by Weight 2 5 26.00 M00 28.32 w0 27.42 C210 0.81 BaO 8.37 F8304 9.08. 

1. AN ABSORPTIVE GLASS MATERIAL OF A COMPOSITION CONSISTING ESSENTIALLY OF THE FOLLOWING INGREDIENTS:
 2. An absorptive glass material according to claim 1 and having the following ingredients:
 3. An absorptive glass material according to claim 1 and having the following ingredients:
 4. An absorptive glass material according to claim 1 and having the following ingredients:
 5. An absorptive glass material according to claim 1 and having the following ingredients:
 6. An absorptive glass material according to claim 1 and having the following ingredients:
 7. An absorptive glass material according to claim 1 and having the following ingredients:
 8. An absorptive glass material according to claim 1 and having the following ingredients: 